Paraduodenal pancreatitis: benign and malignant mimics at MRI

Paraduodenal pancreatitis, also known as groove pancreatitis, is a rare form of chronic pancreatitis that masquerades as pancreatic adenocarcinoma affecting the pancreaticoduodenal groove, a potential space between the head of the pancreas, duodenum, and common bile duct. Two forms of groove pancreatitis have been described. The segmental form involves the pancreatic head with development of scar tissue within the groove, whereas the pure form affects the groove only, sparing the pancreatic head. Imaging findings of groove pancreatitis often overlap with primary duodenal, ampullary, or pancreatic neoplasms, which often results in a diagnostic challenge. In addition, paraduodenal pancreatitis can be mistaken for cystic pancreatic lesions, especially when there is involvement of the duodenal wall. Preoperative recognition of this entity is very important in order to avoid unnecessary procedures, although surgery, such as pancreaticoduodenectomy, may still be required to relieve obstructive symptoms. In this article, the pathophysiology and magnetic resonance imaging characteristics of paraduodenal pancreatitis and important benign and malignant mimics are discussed.

     

Endosonography of groove pancreatitis.

Groove pancreatitis is a rare form of chronic pancreatitis. Distinction between pancreatitis and pancreatic carcinoma is often difficult. Two cases of groove pancreatitis diagnosed by endosonography are described. A hypoechoic pattern between the duodenal wall and pancreas was clearly imaged in both patients. Narrowing of the second part of the duodenum and evidence of bile duct obstruction were also found. The endosonographic diagnosis was confirmed either by surgery or follow-up examination.     

硬化性胰腺炎超声显像及其病理基础

本文对硬化性胰腺炎超声显像及其病理基础作了初步探讨,结果显示:胰腺不规则增大,周边轮廓模糊,腺体回声不均质,可见类肿块样回声,胰管不规则扩张,可伴有肝外胆道梗阻征像,其病理基础为胰腺小叶萎缩,腺体内纤维组织不均匀增生,胰管不规则增厚,纤维组织增生所致.硬化性胰腺炎与胰头癌比较,超声表现非常相似,二者不易鉴别.     

Duodenal duplication cyst: a rare cause of acute pancreatitis in children

Duodenal duplication is a rare cause of acute pancreatitis in children. We report a case of acute pancreatitis in which abdominal sonography revealed an enlarged hypoechoic edematous pancreas with mildly dilated main pancreatic duct and a cystic structure with layered wall in the second part of duodenum. Abdominal CT yielded similar findings. The diagnosis of duodenal duplication was confirmed at surgery and subsequent histopathologic examination.     

Abdominal ultrasonogram of autoimmune pancreatitis: Five cases of pancreatic lesions accompanied by Sjögren syndrome

The concept of autoimmune pancreatitis has recently been established, and ultrasonographic findings we obtained from five cases consistent with autoimmune pancreatitis are reported here. Case 1, a 77-year-old man, was admitted complaining of loss of body weight. Serum hepatobiliary enzymes and γ-globulin levels were elevated, and antinuclear antibody was positive, Abdominal ultrasonography showed dilatation of the intrahepatic bile duct, wall thickening of the common bile duct and hypoechoic swelling of the pancreatic head and body. ERCP revealed multiple stenosis of the intra-and extra-hepatic bile ducts, and diffuse irregular narrowing of the main pancreatic duct. The patient complained of thirst, and the minor salivary gland was examined histologically. Our diagnosis was Sjögren syndrome accompanied by sclerosing cholangitis and a pancreatic lesion. Obstructive jaundice also developed, and PTCD was therefore performed. Both the pancreatic swelling and multiple stenosis of the bile duct improved after steroids were administered. Case 2, a 71-year-old man, was admitted with jaundice. Abdominal ultrasonography showed hypoechoic swelling of the pancreas. ERCP showed stenosis of the common bile duct in the pancreatic head region and diffuse irregular narrowing of the main pancreatic duct. Histological examination of the minor salivary gland suggested Sjögren syndrome. Steroids were therefore administered because the presence of both hyper-γ-globulinemia and positive antinuclear antibody suggested involvement of the autoimmune mechanism. Steroid therapy improved the jaundice as well as the findings from the cholangiograms and pancreatograms. We also encountered three similar cases, all consistent with the concept of autoimmune pancreatitis. The ultrasonographic findings of the pancreatic lesion (1) showed them as homogeneous and markedly hypoechoic areas and, (2) visualized the main pancreatic duct in the lesion, which facilitated a differential diagnosis of the neoplastic lesions. (3) Steroid therapy effectively decreased the hypoechoic area; in some cases, however, a hypoechoic area remained around the main pancreatic duct.     

胰周淋巴结结核的CT及MRI诊断价值

目的:探讨胰周淋巴结结核的CT及MRI表现及其诊断价值。方法:回顾性分析11例经组织学检查或临床追踪证实为胰周淋巴结结核的临床资料。结果:11例CT平扫中4例表现为胰周软组织密度的淋巴结肿大;5例表现为胰头区软组织肿块影;2例表现为淋巴结钙化。增强扫描4例胰周的淋巴结肿大呈环形强化,5例平扫示胰头区病灶为多个淋巴结彼此融合而成,环形强化的淋巴结形成多房样征象;2例淋巴结钙化的病灶表现为无强化。3例MRI平扫示胰头区软组织肿块影,T1WI呈稍低信号,T2WI上呈稍高信号,增强扫描时呈多房样强化。8例合并腹内脏器结核,8例合并肺结核。结论:平扫呈软组织密度的淋巴结肿大或淋巴结钙化,增强扫描病灶呈环形强化或多房样强化是胰周淋巴结结核的最常见的征象,影像学表现比较有特异性。     

原发性十二指肠神经内分泌肿瘤的CT表现

目的 探讨原发性十二指肠神经内分泌肿瘤的CT表现.方法 回顾性分析经病理证实的10例十二指肠神经内分泌肿瘤的多层螺旋CT表现.结果 病灶多位于十二指肠近段(十二指肠球部3例、降部6例、水平部1例);6例表现为腔内息肉状肿块,4例表现为壁内肿块;最大径1.6～6.5 am,平均2.3 cm.CT平扫呈等或稍低密度,平均CT值为41HU;密度均匀者7例,不均匀者3例;所有病灶均未见钙化.增强检查动脉期肿块明显强化,门脉期和平衡期强化程度逐渐降低,均匀强化者6例,不均匀强化者4例,三期增强扫描平均CT值分别为95 HU、83 HU、65 HU.肝内外胆管扩张2例;腹腔及腹膜后淋巴结肿大4例;胰腺受累1例;术后复发并侵犯血管1例.结论 十二指肠神经内分泌肿瘤三期动态增强CT表现有一定特征性,发现早期明显强化对诊断具有较高价值.     

Bile duct involvement in hepatocellular carcinoma: MR demonstration

Background: To determine the magnetic resonance (MR) features of hepatocellular carcinoma (HCC) with associated bile duct involvement. Methods: MR examinations of six patients (mean age, 62 years) demonstrating bile duct involvement due to HCC were retrospectively reviewed and compared to surgical and pathologic findings. Results: Three of the tumors were solitary, and three were multifocal. In two patients, MR showed direct biliary duct invasion by tumor. On T1-weighted MR images, four tumors were hypointense compared to the liver and two were isointense. On T2-weighted MR images, four tumors were hyperintense, and two were isointense. The two tumors studied with dynamic T1-weighted MR images obtained after intravenous administration of a gadolinium chelate, displayed enhancement similar to that of the liver. There was no evidence of a tumor capsule on either unenhanced or enhanced MR images. Intrahepatic bile duct dilatation was seen in five patients. The extrahepatic bile duct was normal in all cases. Conclusion: Although rare, HCC should be included when considering the etiology of intrahepatic bile duct obstruction. Imaging features suggestive of the diagnosis by MR include intrabiliary tumor or bile duct obstruction with an associated hepatic mass.     

Sonographic diagnosis of Ascaris-induced cholecystitis and pancreatitis in a child

We describe the sonographic diagnosis of Ascaris-induced acute cholecystitis and pancreatitis in a 2-year-old girl. Abdominal sonography revealed a grossly distended gallbladder with a thick (0.5-cm) wall. The common bile duct was dilated to 0.6 cm without sludge or calculi. The pancreas was hypoechoic, with an enlarged, 3.3-cm pancreatic head. Sonography showed dilatation of the small- and large-bowel loops, with multiple roundworms in duodenal and colonic loops. Sonography has an important role not only in the diagnosis of this uncommon condition but also in the documentation of its unusual etiologic agent.     

Imaging and clinical features of xanthogranulomatous pancreatitis: an analysis of 10 cases at a single institution

Purpose

The purpose of the study was to investigate the imaging and clinical features of xanthogranulomatous pancreatitis (XGP).

Methods

This retrospective series study included 10 patients with pathology-proven XGP. Two radiologists reviewed the computed tomography (CT) and magnetic resonance imaging (MRI) in consensus to determine the morphological features of XGP. The lesion enhancement pattern on dynamic contrast-enhanced scans and the MR signal intensity were also evaluated. Clinical data including symptoms, underlying pancreatic disease, and laboratory findings were reviewed.

Results

Two XGP cases were of a solid type; six were of cystic type, and two were mixed type. XGP usually showed a lobulated contour (90%) and heterogeneous enhancement (100%), with lesion size varying from 2 to 11 cm. Perilesional infiltration was common (90%), but pancreatic duct dilatation was less frequent (30%). Cystic type XGP mostly had an irregular thick wall (83%). On dynamic contrast-enhanced CT/MRI, XGP enhanced progressively from arterial to portal or delayed phases. Lesions appeared hypointense on T1-weighted images (89%) and hyperintense on T2-weighted images (100%). All lesions appeared hyperintense on diffusion-weighted images, with the majority (78%) showing diffusion restriction on apparent diffusion coefficient maps. The patients often had abdominal pain (80%) and underlying pancreatic disease (80%), but mostly had normal or clinically insignificant laboratory findings.

Conclusions

XGP typically manifests as a clinically silent lobulated heterogeneous mass, with a progressive enhancement pattern and/or irregular thick wall, and diffusion restriction on CT/MRI. Awareness of the imaging and clinical features of XGP may help differentiate it from pancreatic neoplasms, thereby reducing unnecessary surgery.

     

Sonographic diagnosis of choledochocele

We present a case of a 48-year-old female with a history of cholecystectomy and recurrent attacks of pancreatitis whose initial abdominal sonography (US) revealed multiple conglomerated stones in the descending part of the duodenum. Abdominal CT, MRI, and magnetic resonance cholangiopancreatography showed the same findings. The distended sacciform distal intramural segment of the common bile duct was protruding into the duodenum. The imaging findings explained the etiology of the patient's recurrent attacks of pancreatitis and led to surgical excision of the choledococele.     

Autoimmune pancreatitis: radiologic findings in 20 patients

Background Autoimmune pancreatitis is a new clinical entity that is characterized by peculiar histopathologic and laboratory findings and by a dramatic clinical response to corticosteroid therapy. We evaluated the radiologic findings of autoimmune pancreatitis. Methods Computed tomographic, magnetic resonance imaging, endoscopic retrograde cholangiopancreatographic, and ultrasonographic findings of 20 patients with autoimmune pancreatitis in our hospital between November 2000 and December 2003 were retrospectively reviewed regarding changes and ancillary findings in the pancreatic parenchyma, the main pancreatic duct, peripancreatic vessels, and distal common bile duct. In addition, follow-up images were reviewed for changes in any abnormality seen on the initial examinations. Results Pancreatic parenchymal enlargement was invariably seen that was diffuse (n = 19) or focal (n = 1), with homogeneous contrast enhancement on computed tomography (n = 20) and magnetic resonance imaging (n = 15). Capsule-like rim enhancement was seen in six patients. There was focal (n = 18) or diffuse (n = 2) narrowing of the main pancreatic duct and it was usually multifocal (n = 17) in the former. Narrowing of the peripancreatic veins was seen in 14 patients. There was tapered (n = 15) or abrupt (n = 3) narrowing of the distal common bile duct in 18 patients, with contrast enhancement of the narrowed segment in eight. Invariably, changes in the pancreatic parenchyma, main pancreatic duct, peripancreatic vessels, and common bile duct were normalized on follow-up studies after steroid therapy. Conclusion In this series, common radiologic findings of autoimmune pancreatitis were (a) diffuse pancreas enlargement, (b) multifocal narrowing of the main pancreatic duct, (c) narrowing of peripancreatic veins, and (d) tapered narrowing of the distal common bile duct with frequent contrast enhancement. These findings were usually reversible with steroid therapy.     

十二指肠乳头部肿瘤的超声诊断价值

【目的】探讨十二指肠乳头部肿瘤的超声征象及其与临床病理的相关性。【方法】对14例常规经腹超声怀疑十二指肠乳头部肿瘤的患者的临床、病理及声像图特征进行分析。【结果】9例病理及胃镜证实十二指肠乳头部病变（7例恶性,2例潜在恶性）,4例胆总管下段腺癌侵及十二指肠乳头及肠壁,1例十二指肠降部憩室。声像图特征：①以低回声多见,边界较模糊,无明显包膜;②形态多为不规则结节状;③病灶内可见偏心气体强回声,或周边可见肠气、肠壁蠕动。【结论】在经腹常规超声检查中十二指肠乳头部肿瘤有其影像特征,注意肿块与十二指肠肠壁的关系是诊断及鉴别诊断的要点。     

Periduodenal panniculitis due to spontaneous rupture of a pancreatic pseudocyst into the duodenum

We report a patient with transient periduodenal panniculitis due to spontaneous rupture of a pancreatic pseudocyst into the duodenum. He developed sudden onset of severe epigastric and back pain with jaundice, mimicking the symptoms of acute pancreatitis. However, the serum and urinary amylase levels did not increase. CT scans showed disappearance of his pseudocyst and periduodenal panniculitis without any evidence of acute pancreatitis. The CT findings of periduodenal panniculitis and his symptoms both improved within 3 weeks. A duodenal fistula leading to the remnant pseudocyst and narrowing of the periduodenal portion of the common bile duct were demonstrated by endoscopic retrograde cholangiopancreatography.     

Choledochocele: diagnosis by magnetic resonance imaging

The value of magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) is demonstrated in a case of a 22-year-old female with a small choledochocele clinically presenting with acute cholecystitis and pancreatitis. Previous abdominal sonography and computed tomography were not diagnostic. MRI and MRCP showed a cystic dilatation of the distal common bile duct, intramurally located in the second portion of the duodenum and protruding into the duodenal lumen. These findings allowed a confident diagnosis of a choledochocele. Received: 8 December 1999/Accepted: 12 January 2000     

多层螺旋CT在恶性低位胆道梗阻疾病诊断中的应用研究

目的探讨多层螺旋CT成像鉴别不同组织来源的恶性低位胆道梗阻疾病的诊断价值。 方法回顾性分析新疆维吾尔自治区儿童医院2015年3月至2017年12月经手术或经内镜逆行性胰胆管造影术活检证实的恶性低位胆道梗阻患者30例的临床资料。总结术前多层螺旋CT诊断的胆管癌、胰头癌和壶腹癌的影像学表现，并与病理活检结果进行对照，采用Kappa检验判断术前诊断与术后病理诊断的一致性。 结果30例患者多层螺旋CT均可清晰显示胆道系统扩张及远端梗阻部位胆管壁增厚、管腔狭窄。胆管癌表现为肝内胆管中、重度扩张，远端胆管呈"截断征"，梗阻部位可见软组织密度肿块沿胆管侧壁向管腔内生长；壶腹癌患者胆总管、胰管均扩张，呈典型"双管征"；胰头癌患者肿块密度不均，边界不清，强化不明显，呈相对低密度，胰体尾部常萎缩。多层螺旋CT诊断胆管癌准确性、敏感度、特异度分别为88.9%、88.9%、83.3%；诊断胰头癌准确性、敏感度、特异度分别为75.0%、85.7%、91.3%；诊断壶腹癌准确性、敏感度、特异度分别为75.0%、60.0%、96.0%。多层螺旋CT诊断与病理检查诊断结果经Kappa一致性检验分析，κ=0.70，P<0.01。 结论多层螺旋CT对于引起恶性梗阻性黄疸的壶腹区肿瘤术前诊断与病理诊断有较好一致性，能清晰显示胆道梗阻部位、程度、肿块以及与周围血管的关系，可作为临床诊断的常规影像学手段。     

Autoimmune pancreatitis: with special reference to a localized variant

In 2006, the Japan Pancreas Society revised the diagnostic criteria for autoimmune pancreatitis (AIP) so as to more clearly define its morphological, pathological, and immunological features, as follows: (1) diffuse or segmental narrowing of the main pancreatic duct with an irregular wall and diffuse or localized enlargement of the pancreas recognized by imaging studies; (2) high serum gamma globulin, IgG, or IgG4 levels, or the presence of autoantibodies; and (3) marked interlobular fibrosis and prominent infiltration of lymphocytes and plasma cells in the periductal area, occasionally with lymphoid follicles in the pancreas. Establishing a diagnosis of AIP has become easier with knowledge of its immunological abnormalities, including serum IgG4 levels. However, the localized form of AIP sometimes mimics pancreatic cancer. The rate of focal mass formation in patients with AIP is reportedly 24%–43%; however, there have been few reports on the histological findings of localized AIP, in contrast to mass-forming pancreatitis (MFP). Our review of patients who had undergone resection due to a preoperative diagnosis of MFP with possible cancer revealed 72% to be patients with localized AIP. For the discrimination of these conditions, it is important to recognize the characteristic ultrasonographic findings of AIP, i.e., (1) diffuse or localized enlargement and hypoechogenicity of the pancreas; (2) rarity of calcification, cystic lesions, and peripancreatic fluid collection; (3) thickened layer structure of the bile duct wall; (4) iso/hypervascularity in the swollen portion of the pancreas; (5) attenuation of pancreatic swelling and bile duct wall thickening after steroid therapy; and (6) multiple hypoechoic masses in various organs, including the pancreas. Contrast-enhanced endoscopic ultrasonography is potentially a useful tool in the differential diagnosis and for assessment of the efficacy of steroid therapy by enabling evaluation of the vascularity of the lesions. Along with the presence of IgG4-positive plasma cells, verification of obliterative phlebitis is highly specific for the histological diagnosis of AIP.     

沟槽状胰腺炎6例分析

目的探讨沟槽状胰腺炎的诊断和治疗。方法回顾性分析1989年1月至2003年1月间在本院因疑为胰头癌而行胰十二指肠切除,术后病理证实为沟槽状胰腺炎的6例患者。结果本组6例患者中,临床表现包括波动性黄疸,上腹部隐痛不适、呕吐、体质量减轻,术前诊断为胰头癌;手术后,除1例死于术后并发症,1例失访外,余4例至今存活。结论沟槽状胰腺炎的临床表现和影像学检查均无特异性,超声内镜检查有助于诊断;诊断时,应注意与胰头癌相鉴别;不同的患者,可采用不同的治疗方法．对于严重者,保留幽门的胰头十二指肠切除术有较好的疗效。     

急性坏死性胰腺炎并胰管中断综合征的MRI表现

目的探讨急性坏死性胰腺炎所致胰管中断综合征的MRI特征。方法回顾性分析本院从2010年1月~2016年1月间急性胰腺炎住院病例因局部并发症行外科手术证实胰管中断的患者,均于发病后3~10 d行MRI检查且术前MRI检查。分析首次MRI检查上是否存在胰腺坏死,统计胰腺坏死部位、范围、深度、类型及MRSI评分;评价复查MRI上主胰管中断显示率、中断位置及与胰腺包裹性坏死的关系。结果共纳入胰管中断综合征患者26例(男15例,女11例,年龄50.2±15.2岁)进入研究,首次MRI检查均为急性坏死性胰腺炎,透壁性胰腺坏死占65.4%(17/26)、厚层性胰腺坏死占34.6%(9/26);胰腺内坏死厚度为2.4±0.3 cm(2~3.2 cm),坏死范围:50%者占61.5%(16/26)、30%~50%者占38.5%(10/26),MRSI评分为8.9±0.9分(8~10分)。MRI复查示73.1%(19/26)的患者见主胰管中断综合征的直接征象,即胰体部中断者占57.9%(11/19)、胰体尾交界区中断者占26.3%(5/19)、胰颈部中断者占15.8%(3/19)。所有病例均见胰腺包裹性坏死形成,19例患者上游胰腺组织内的主胰管如"苹果柄"状近直角汇入病灶并相通。结论急性胰腺炎厚层性/透壁性胰腺坏死致胰管中断综合征具有相应的MRI征象,后期出现的胰腺包裹性坏死为胰管中断综合征的并发症,可视为"厚层性/透壁性胰腺坏死-胰管中断-胰腺包裹性坏死"三部曲。     

内镜下局部切除十二指肠乳头病变治疗的研究

目的：探讨内镜下局部切除十二指肠乳头病变方法的安全性及疗效。方法：内镜下采用圈套器对7例确诊为十二指肠乳病变患者取病变乳头进行电凝切除，部分患者切除后为防止胰管或胆管狭窄放置内支架，切除后标本送病理检查，定期随访。结果：7例病变全部完整切除。病理结果为腺瘤2例，局部高度不典型增生3例，乳头癌2例。治疗后黄疸短期内明显降低，胰腺炎无复发。无明显并发症发生。结论：内镜下十二指肠乳头切除术，对于十二指肠乳头腺瘤、局部不典型增生、早期肿瘤等疗效肯定，并可以避免外科手术。